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<h2><span class="refentrytitle">Struct template dim</span></h2>
<p>boost::units::dim — Dimension tag/exponent pair for a single fundamental dimension. </p>
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<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../boost_units/Reference.html#doxygen.units_reference.dim_8hpp" title="Header &lt;boost/units/dim.hpp&gt;">boost/units/dim.hpp</a>&gt;

</span><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> V<span class="special">&gt;</span> 
<span class="keyword">struct</span> <a class="link" href="structboost_1_1units_1_1dim.html" title="Struct template dim">dim</a> <span class="special">{</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <a class="link" href="structboost_1_1units_1_1dim.html" title="Struct template dim">dim</a>         <a name="doxygen.units_reference.structboost_1_1units_1_1dim_1a472a9554df8b8d6bc33edfe2c9ee6727"></a><span class="identifier">type</span><span class="special">;</span>      
  <span class="keyword">typedef</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <a name="doxygen.units_reference.structboost_1_1units_1_1dim_1a5e9991021c6fba125ca468d4c77041a8"></a><span class="identifier">tag</span><span class="special">;</span>       
  <span class="keyword">typedef</span> <span class="identifier">T</span>           <a name="doxygen.units_reference.structboost_1_1units_1_1dim_1a35b82a36328d694c0acdbb1f1a8aa8c8"></a><span class="identifier">tag_type</span><span class="special">;</span>  
  <span class="keyword">typedef</span> <span class="identifier">V</span>           <a name="doxygen.units_reference.structboost_1_1units_1_1dim_1aa27d946457c40d3934e759a3ca79ab74"></a><span class="identifier">value_type</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.42.10.2.9.4.4"></a><h2>Description</h2>
<p>The dim class represents a single dimension tag/dimension exponent pair. That is, <code class="computeroutput">dim&lt;tag_type,value_type&gt;</code> is a pair where <code class="computeroutput">tag_type</code> represents the fundamental dimension being represented and <code class="computeroutput">value_type</code> represents the exponent of that fundamental dimension as a <code class="computeroutput"><a class="link" href="classboost_1_1units_1_1static__rational.html" title="Class template static_rational">static_rational</a></code>. <code class="computeroutput">tag_type</code> must be a derived from a specialization of <code class="computeroutput"><a class="link" href="classboost_1_1units_1_1base__dimension.html" title="Class template base_dimension">base_dimension</a></code>. Specialization of the following Boost.MPL metafunctions are provided - @c mpl::plus for two @c dims
- @c mpl::minus for two @c dims
- @c mpl::negate for a @c dim
</p>
<p>These metafunctions all operate on the exponent, and require that the <code class="computeroutput">dim</code> operands have the same base dimension tag. In addition, multiplication and division by <code class="computeroutput"><a class="link" href="classboost_1_1units_1_1static__rational.html" title="Class template static_rational">static_rational</a></code> is supported. - @c mpl::times for a @c static_rational and a @c dim in either order
- @c mpl::divides for a @c static_rational and a @c dim in either order
</p>
<p>These metafunctions likewise operate on the exponent only. </p>
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<div class="copyright-footer">Copyright © 2003-2008 Matthias Christian Schabel<br>Copyright © 2007-2010 Steven
      Watanabe<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
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